金属橡胶用Cr-Ni-Mn系不锈钢丝的微观组织及力学性能研究

采用光学显微镜、扫描电镜、X射线相定量分析等技术,研究了制备金属橡胶构件用冷变形量分别为36%,64%,84%和91%所得的直径0.4mm,0.3mm,0.2和0.15mm的Cr-Ni-Mn系不锈钢丝的微组织结构和力学性能的变化规律.结果表明,冷拔钢丝中出现了形变马氏体,冷变形量为36%时的马氏体含量已达81.2%,即用于制作金属橡胶构件时奥氏体不锈钢已实际处于以马氏体为主的高强度状态,而非奥氏体状态,且马氏体数量随冷拔变形量有增大趋势;钢丝内部出现平行于拉拔方向的拉长孔洞,其体积分数随冷拔变形量的增大而增加.同时,在所用冷拔变形量条件下,不锈钢微丝的抗拉强度高达1406～2244MPa,延伸率则在13.0%～8.9%范围内变化.从而可以判断,采用上述微丝制作的金属橡胶将是以马氏体相之为主且具有微观和宏观尺度双重尺寸孔洞(孔隙)的多孔金属材料.

Microstructure and Mechanical Properties of Stainless Steel Wires Used for Metal Rubber

The microstructure and mechanical properties of stainless steel wires used for metal rubber were studied by means of optical microscopy,SEM,and X-ray diffraction.The wire diameters were 0.4,0.3,0.2,and 0.15mm,which were obtained by cold drawn of 36%,64%,84% and 91%,respectively.The deformation-induced martensite content in the wires increased with the deformation,starting from 81.2% at 36% deformation.The microstructures of metal rubber produced using these wires should mainly consist of martensite other than austenite,although the experimental material is a typical austenitic stainless steel.SEM observations showed that there were large quantities of voids parallel to the drawing direction,whose volume fractions increased with the deformation.Meanwhile,the tensile strengths of the wires were 1406~2244MPa, the elongations were 13.0%~8.9%.Therefore,we can conclude that the metal rubber produced by such wires should mainly consist of martensite and bear both micro-and macro-voids or porosities.